A lens body that is arranged in front of a light source and configured to control light from the light source to form a predetermined light distribution pattern including a cutoff line at the upper edge thereof has heretofore been proposed (for example, see Japanese Patent Application Laid-Open No. 2004-241349 or US2004/156209A1 corresponding thereto).
FIG. 1 is a longitudinal cross-sectional view of a lens body 220 (vehicle lighting fixture 200) described in Japanese Patent Application Laid-Open No. 2004-241349.
As illustrated in FIG. 1, the lens body 220 described in Japanese Patent Application Laid-Open No. 2004-241349 is to be arranged in front of a light source 210 including a semiconductor light emitting element. The surface of the lens body 220 includes an incident surface 221 of semispherical shape, a first reflection surface 222, a second reflection surface 223, and a convex lens surface 224. The light source 210 is arranged with its light emitting surface upward. The incident surface 221 covers the light source 210 from above. The first reflection surface 222 is arranged in a traveling direction of light from the light source 210, the light entering the interior of the lens body 220 from the incident surface 221. The second reflection surface 222 extends forward from a lower edge of the first reflection surface 222.
The lens body 220 (vehicle lighting fixture 200) having the foregoing configuration has the following problem.
The first reflection surface 222 and the second reflection surface 223 are configured as reflection surfaces (having a reflectance of about 95% at most) formed by metal deposition applied to the surface of the lens body 220. There is therefore a problem of low light use efficiency because the reflection surfaces 222 and 223 formed by the metal deposition cause reflection loss (light loss). There is also a problem of a cost increase because the application of the metal deposition needs facilities, processes, metal materials, etc. The reflection surfaces 222 and 223 (reflection films) formed by the metal deposition also have a problem of low durability.